Abstract : The objective of the Upper Atmosphere Project is the design and construction of a facility to study flow conditions that would be encountered by a vehicle traveling through the upper atmosphere at velocities up to escape velocity in the region of free molecule flow. The study would involve such factors as; the simulation of the impact of molecules on a surface from sub-circular to super-circular velocities in the free molecule flow regions, and the related systems, techniques, and detection instrumentation for such a facility. The work would also include the evaluation and analysis for each known simulation method and a recommendation for the most desirable approach, and the accompanying design study with a complete description of the proposed facility and its instrumentation. The purpose of this initial report is to investigate the relevant problems of a vehicle in the free molecule flow regime of the upper atmosphere and to study the problems concerning the surface history of a vehicle traversing, or re-entering this region. This study would be concerned with the various types of reflection, the accommodation coefficient, and the interaction of the surface and the gas molecules, also, impacts resulting in mechanical erosion whereby molecules are knocked out of the skin surface. (Author)